Ash Way Urban Center – Critical Area Permits & Wetland and Stream Restoration

If you have driven on I-5 North recently you might have noticed several new buildings near the exit for 164th Street SW in Lynnwood. The new development is Ash Way Urban Center, a multi-family development that is pedestrian oriented to take advantage of the adjacent regional Park and Ride transit station. Raedeke Associates, Inc. (RAI) conducted field studies, obtained the critical area permits, and prepared the wetland and stream restoration plan as mitigation for the development.

During the beginning phase of the project, RAI delineated two wetlands and a ditched stream on this 9-acre site. In order to construct the project, it was necessary to fill a portion of one of these wetlands, requiring permits from local, state, and federal agencies. RAI evaluated project impacts on the wetlands and stream in order to prepare a mitigation plan that was required for these permits. For the federal permit application to the U.S. Army Corps of Engineers, we also completed a biological evaluation of project impacts to fish and wildlife species listed as threatened or endangered under the federal Endangered Species Act.

RAI provided landscape architectural design services to prepare a mitigation plan that would restore wetland and stream functions that had been reduced or lost from previous human activities and from the wetland fill that would be required for project construction. The plan included removing old fill from one of the wetlands to restore the historic water regime and enhancing the both wetlands and their buffers by removing noxious weeds, planting native species, and installing habitat features including snags and logs. The ditched stream was re-meandered to a more natural configuration, fish friendly gravel was laid on the streambed, and the stream banks were planted with native riparian vegetation well-adapted to the site conditions. The wetland and stream restoration areas and their buffers will be monitored and maintained for 5 years to ensure that they meet specific goals of the mitigation plan.

The restoration plan also included construction of a trail within the wetland buffer using pervious materials. The intent of the trail is for public access to the wetlands and stream to allow low-impact recreation and to provide environmental education opportunities regarding their value. As part of the environmental education component of the project, we designed three trail-side interpretive signs regarding wetland functions, wildlife habitat, and fish habitat that would be provided by the wetland and stream restoration. Implementation of the wetland and stream restoration plan was completed this year, and people are starting to occupy Ash Way Urban Center and use the trail.